1.Preheat oven to 150°C. Grease oven trays; line with baking paper.
2.In a small bowl, beat egg whites with electric mixer until soft peaks form. Add caster sugar and a few drops of colouring; beat until sugar dissolves. Transfer mixture to a large bowl.
3.Push blackberries through fine sieve into small bowl; you need 1 tablespoon of blackberry puree.
4.Fold sifted icing sugar, ground almonds and puree into egg white mixture, in two batches.
5.Spoon mixture into piping bag fitted with 1cm plain tube. Pipe 3cm rounds, about 2.5cm apart, onto trays. Tap trays on bench so macaroons spread slightly. Stand 45 minutes or until macaroons feel dry to touch.
6.Bake about 15 minutes. Cool on trays.
7.Sandwich macaroons with jam. Dust with extra sifted icing sugar.
If you don’t have purple food colouring, use a few drops each of red and blue food colouring until the desired shade of purple is achieved.Note